From: Frederick Grose <fgrose@xxxxxxxxxxxxx>
commit 96ff19a87c0be1eca27860aeef5434513b0e8c61
Author: Frederick Grose <fgrose@xxxxxxxxxxxxx>
Allow read-only mounting of the base device filesystem, livedev.
Use read-only loop devices and non-persistent overlay targets.
---
modules.d/90dmsquash-live/dmsquash-live-root.sh | 25 ++++++++++++++++---------
1 file changed, 16 insertions(+), 9 deletions(-)
diff --git a/modules.d/90dmsquash-live/dmsquash-live-root.sh b/modules.d/90dmsquash-live/dmsquash-live-root.sh
index 14e84e1..af0022f 100755
--- a/modules.d/90dmsquash-live/dmsquash-live-root.sh
+++ b/modules.d/90dmsquash-live/dmsquash-live-root.sh
@@ -24,7 +24,7 @@ squash_image=$(getarg rd.live.squashimg)
getargbool 0 rd.live.ram -d -y live_ram && live_ram="yes"
getargbool 0 rd.live.overlay.reset -d -y reset_overlay && reset_overlay="yes"
-getargbool 0 rd.live.overlay.readonly -d -y readonly_overlay && readonly_overlay="--readonly" || readonly_overlay=""
+getargbool 0 rd.live.overlay.readonly -d -y readonly_overlay && readonly_overlay="-r" || readonly_overlay=""
overlay=$(getarg rd.live.overlay -d overlay)
# CD/DVD media check
@@ -105,17 +105,23 @@ do_live_overlay() {
setup=""
if [ -n "$devspec" -a -n "$pathspec" -a -n "$overlay" ]; then
mkdir -m 0755 /run/initramfs/overlayfs
- mount -n -t auto $devspec /run/initramfs/overlayfs || :
- if [ -f /run/initramfs/overlayfs$pathspec -a -w /run/initramfs/overlayfs$pathspec ]; then
- losetup $OVERLAY_LOOPDEV /run/initramfs/overlayfs$pathspec
- if [ -n "$reset_overlay" ]; then
- dd if=/dev/zero of=$OVERLAY_LOOPDEV bs=64k count=1 conv=fsync 2>/dev/null
+ mount -n -t auto -o $liverw $devspec /run/initramfs/overlayfs || :
+ if [ -f /run/initramfs/overlayfs$pathspec ]; then
+ if [ "$liverw" = ro ]; then
+ readonly_overlay='-r'
+ fi
+ losetup $readonly_overlay $OVERLAY_LOOPDEV /run/initramfs/overlayfs$pathspec
+ if [ -w /run/initramfs/overlayfs$pathspec ]; then
+ if [ -n "$reset_overlay" ]; then
+ dd if=/dev/zero of=$OVERLAY_LOOPDEV bs=64k count=1 conv=fsync 2>/dev/null
+ fi
fi
setup="yes"
fi
umount -l /run/initramfs/overlayfs || :
fi
+ persistent='P'
if [ -z "$setup" -o -n "$readonly_overlay" ]; then
if [ -n "$setup" ]; then
warn "Using temporary overlay."
@@ -123,6 +129,7 @@ do_live_overlay() {
warn "Unable to find persistent overlay; using temporary"
sleep 5
fi
+ persistent='N'
dd if=/dev/null of=/overlay bs=1024 count=1 seek=$((512*1024)) 2> /dev/null
if [ -n "$setup" -a -n "$readonly_overlay" ]; then
@@ -136,14 +143,14 @@ do_live_overlay() {
# set up the snapshot
sz=$(blockdev --getsz $BASE_LOOPDEV)
if [ -n "$readonly_overlay" ]; then
- echo 0 $sz snapshot $BASE_LOOPDEV $OVERLAY_LOOPDEV p 8 | dmsetup create $readonly_overlay live-ro
+ echo 0 $sz snapshot $BASE_LOOPDEV $OVERLAY_LOOPDEV N 8 | dmsetup create $readonly_overlay live-ro
base="/dev/mapper/live-ro"
over=$RO_OVERLAY_LOOPDEV
else
base=$BASE_LOOPDEV
over=$OVERLAY_LOOPDEV
fi
- echo 0 $sz snapshot $base $over p 8 | dmsetup create live-rw
+ echo 0 $sz snapshot $base $over $persistent 8 | dmsetup create live-rw
}
# live cd helper function
@@ -217,7 +224,7 @@ fi
if [ -b "$OSMIN_LOOPDEV" ]; then
# set up the devicemapper snapshot device, which will merge
# the normal live fs image, and the delta, into a minimzied fs image
- echo "0 $( blockdev --getsz $BASE_LOOPDEV ) snapshot $BASE_LOOPDEV $OSMIN_LOOPDEV p 8" | dmsetup create --readonly live-osimg-min
+ echo "0 $( blockdev --getsz $BASE_LOOPDEV ) snapshot $BASE_LOOPDEV $OSMIN_LOOPDEV N 8" | dmsetup create --readonly live-osimg-min
fi
ROOTFLAGS="$(getarg rootflags)"
--
1.8.3.1
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